(1) Field of the Invention
The present invention relates to a manufacturing method of a resin-molding type semiconductor device, and a wiring board therefor.
(2) Description of the Related Art
A conventional method for manufacturing a resin-molding type semiconductor device is disclosed, for example, in JP2002-246336A. According to this method, a plurality of semiconductor elements are mounted on a wiring board, and then are collectively sealed with a resin. The wiring board is then divided into one or more semiconductor elements by a dicing process.
FIGS. 14A to 14C are plan views and a sectional view, respectively, illustrating a wiring board serving as a base material for a semiconductor device. The wiring board 1 has the following configuration. A plurality of element regions 6 each have a mount region 2 on which a semiconductor element is mounted. An electrode wire 21 (including wires 3, via holes 4 for internal layer interconnection, and electrode terminals 5) serves as a product circuit. The element regions and electrode wires are arranged in a matrix form to form a product region 7, and a peripheral region 8 surrounds the product region 7. Further, a plurality of seal regions 9, each including such product region 7 and such peripheral region 8 sealed with a resin, collectively, are arranged side by side with slits 10 interposed therebetween.
FIG. 15A to 15D are sectional views and plan views each illustrating a conventional method for manufacturing a resin-molding type semiconductor device. As illustrated in FIG. 15A, first, a semiconductor element 11 is mounted on a mount region 2 of each element region 6 (i.e., a product region 7) in a wiring board 1, and is electrically connected to an electrode wire 21 through a thin, metal wire 12 or the like. Then, a seal region 9 larger in size than the product region 7 is sealed with a resin 13 by collective molding; thus, a resin-molded body 14 is formed. The resin-molded body 14 is divided at slits 10 if necessary.
As illustrated in FIGS. 15B to 15D, next, dicing tape 15 is affixed to a surface of the resin-molded body 14. The resin-molded body 14 is subjected to dicing by means of a dicing blade 16 from a back side of the wiring board 1. The resin-molded body 14 is thus divided into individual semiconductor devices corresponding to the respective element regions 6.
First, the resin-molded body 14 is sequentially cut along cutting lines La, Lb, Lc and Ld in a certain direction, and then it is sequentially cut along cutting lines Le, Lf, Lg and Lh perpendicular to the cutting lines La, Lb, Lc and Ld. In other words, the resin-molded body 14 is first divided into narrow resin-molded body pieces, which are divided into semiconductor devices.
When the resin-molded body pieces are cut, an area outside the product region 7 is also cut (see FIG. 15D). If the dicing blade 16 is rotated at a high speed or is moved rapidly, the resin 13 in the area outside the product region 7 may be peeled off from the dicing tape 15 at the end of the cutting of the spacing, so that the spacing is scattered.
During cutting, the wiring board 1 absorbs any vibration or a stress generated by the rotation of the dicing blade 16 because the wiring board 1 is relatively soft. But the resin 13 is heavily stressed by the vibration. As the cutting of the spacing proceeds, a shearing force becomes small, so that the resin 13 in the spacing cannot endure the stress. Consequently, the resin 13 in the spacing is peeled off from the dicing tape 15. This results in the spacing being scattered. Another reason for such scattering is as follows: bonding between the spacing and the dicing tape 15 is unstable because a portion corresponding to the wiring board 1 is longer than a portion corresponding to the resin 13 in the spacing (see FIG. 15B).
Thus, the resin 13 in the corner of the element region 6 is scattered together with the resin 13 in the spacing immediately before completion of the cutting. Consequently, the resin 13 in a corner of a semiconductor device becomes chipped. In addition, the scattered spacing or the resin in such spacing collides with the dicing blade 16, and the dicing blade 16 may be damaged. In FIG. 15D, a shaded portion is readily scattered.
To overcomethese problems, conventionally, the resin 13 in the spacing is prevented from being peeled off from the dicing tape 15 by slowly rotating or moving the dicing blade 16. Thus, the resin 13 in the corner of the semiconductor device is prevented from becoming chipped and the dicing blade 16 is prevented from being damaged. However, this results in poor productivity.